Fixing my older sigma 400mm prime lens

[sparkie1263]

I would try to get a metal gear and that will solve the problem from happening again.

Frank

[Anthony]

I would think there would be two reasons for a platic gear Frank:
1/ Reduce the noise.
2/ Reduce damage in cases like this - the gear strips and that prevents something else more critical/expensive being broken.

[ericst11]

I agree with anthony on that one its like a cotter pin it breaks before the shaft does so you don't end up with some thing to srewed up. the main gears are medal and the other aren't .